1. Field of the Invention
The present invention relates to air volume control conducted in an air conditioner for vehicle use. More particularly, the present invention relates to air volume control preferably applied to an air conditioner for vehicle use in which a volume of air blown out to a right region in a passenger compartment and a volume of air blown out to a left region therein are independently controlled.
2. Description of the Related Art
Conventionally, the official gazette of Japanese Patent No. 2682627 discloses an air conditioner for vehicle use in which a volume of air blown out to a right region in a passenger compartment and a volume of air blown out to a left region therein are controlled.
This prior art is composed as follows. The inside of a duct connecting a blowout portion of a single blower unit with an entrance portion of a heat exchanger for cooling (evaporator) is partitioned into a right passage and a left passage of a vehicle. An air flow distributing door composed of one plate door is pivotally arranged in this passage partitioning portion. By this one air flow distributing door, a ratio of the opening of the right passage in the duct to the opening of the left passage is changed over, so that a volume of air blown out to the right region in the passenger compartment and a volume of air blown out to the left region therein can be changed.
However, according to the above prior art, the following problems may be encountered. When the opening area of one of the right and left passages in the duct is reduced, the opening area of the other passage is necessarily increased. Therefore, it is difficult to change a volume of air only in one passage. Further, as an air flow distributing door, which is exclusively used for distributing an air blast to the right and left, is arranged in the above structure, it becomes necessary to provide a space in which the air flow distributing door is exclusively arranged. Accordingly, the size of the air conditioner is increased, which makes it difficult to mount the air conditioner on a vehicle.
In this connection, the above prior art describes a case in which a volume of air blown out to the right region of the passenger compartment and a volume of air blown out to the left region therein are controlled. However, the same problems may be encountered in a case in which a volume of air blown out to the front seat side region of the passenger compartment and a volume of air blown out to the rear seat side region therein are controlled.